Search results
Results from the WOW.Com Content Network
Fluorocarbons with few C–F bonds behave similarly to the parent hydrocarbons, but their reactivity can be altered significantly.For example, both uracil and 5-fluorouracil are colourless, high-melting crystalline solids, but the latter is a potent anti-cancer drug.
String theory predicts 1- to 10-branes (a 1-brane being a string and a 10-brane being a 10-dimensional object) that prevent tears in the "fabric" of space using the uncertainty principle (e.g., the electron orbiting a hydrogen atom has the probability, albeit small, that it could be anywhere else in the universe at any given moment).
A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactively decays , usually by emitting an alpha particle . The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes , making them useful for dating the age of the Earth .
As aluminium is a small atom relative to these chalcogens, these have four-coordinate tetrahedral aluminium with various polymorphs having structures related to wurtzite, with two-thirds of the possible metal sites occupied either in an orderly (α) or random (β) fashion; the sulfide also has a γ form related to γ-alumina, and an unusual ...
The adoption of the term "nucleus" to atomic theory, however, was not immediate. In 1916, for example, Gilbert N. Lewis stated, in his famous article The Atom and the Molecule, that "the atom is composed of the kernel and an outer atom or shell." [12] Similarly, the term kern meaning kernel is used for nucleus in German and Dutch.
The electron affinity (E ea) of an atom or molecule is defined as the amount of energy released when an electron attaches to a neutral atom or molecule in the gaseous state to form an anion. X(g) + e − → X − (g) + energy. This differs by sign from the energy change of electron capture ionization. [1]
The school founder's traditional name Kanada means 'atom eater', [45] and he is known for developing the foundations of an atomistic approach to physics and philosophy in the Sanskrit text Vaiśeṣika Sūtra. [46] His text is also known as Kanada Sutras, or Aphorisms of Kanada. [47] [48]
Stoney's most important scientific work was the conception and calculation of the magnitude of the "atom of electricity". In 1891, he proposed the term " electron " to describe the fundamental unit of electrical charge, [ 7 ] and his contributions to research in this area laid the foundations for the eventual discovery of the particle by J. J ...